Printing devices provide a user with a hardcopy of a document by printing a representation of the document from digital data onto a print medium. The printing device, such as a two dimensional (2D) printing device, includes a number of components such as a carriage with a number of pens. The pens are coupled to the carriage and are used to eject printing fluid or other printable material onto the print medium to form an image. The carriage moves along a carriage rail via a motor to eject the printing fluid onto the print medium to form the image. Further, the printing device may be a 3 dimensional (3D) printing device. The 3D printing device uses pens to print on a bed of build material to create a 3D object.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.